[mKilgore]

I'm hoping any of you that have installed a CSF High Performance Radiator can chime in with your experience. In preparation for more regularly tracking my 135i, I have been addressing cooling issues. My car is stock with no tune.

I installed the CSF Radiator, bled the system, took the car out for a drive and after about 5 minutes, the radiator fan kicked on high and my coolant gauge starting going crazy (rapidly changing temperatures from 150F to 400F and everywhere in between). The car also threw a "thermostat jammed open" code (348a).

I ended up taking the car to a local BMW shop for them to run some diagnostics and figure out the deal. They changed the thermostat, but the issue was not resolved. They checked the coolant temp sensor, it was good. The wiring and ecu and other modules are fine. All the parameters and diagnostic checks are normal. We decided to take the CSF radiator out and reinstall the stock radiator to see if it was a radiator related issue. Presto, everything has been back to normal and no problems once the stock radiator went back in.

And please don't tell me "its your water pump". We've tested it and it is fine as well. Hence why I've been driving it with the stock radiator back in and had no problems for a couple hundred miles now.

Any thoughts? Has anyone else installed the CSF radiator on a stock car with no tune and had any problems?